Intel Corp. and STMicroelectronics NV are unloading troubled divisions that make a type of flash memory used primarily in cell phones.

The chip makers and Menlo Park private equity firm Francisco Partners will form a new company that will buy up the assets of Intel’s and STMicro’s NOR flash businesses.

It promises to placate skittish investors concerned about the fading fortunes of NOR flash memory. Overall revenues for the chips were $8.3 billion last year, but the entire segment was unable to turn a profit, according to market researcher iSuppli Corp.

The deal signals the waning importance of NOR flash. Invented by Intel in the late 1980s, it has been steadily losing ground to NAND flash memory — a cheaper alternative that’s used in digital cameras and music players.

Until now, Santa Clara-based Intel, the world’s largest semiconductor company, has stood by its unprofitable business. The division was losing about $150 million a year before Intel formed a joint venture in 2005 with Micron Technology Inc. to produce NAND flash.

The red ink continued last year, with Intel losing about $555 million from the combined businesses due primarily to startup costs for the NAND business. Intel no longer breaks out revenue for NOR flash.

In Tuesday’s deal, Intel will get $432 million in cash for its NOR flash unit. STMicroelectronics will sell its entire flash memory operation, including the NOR division and its stake in a joint venture with Hynix Semiconductor Inc. that makes NAND flash chips, for $468 million.

No name has been chosen for the new company, which will combine businesses that generated some $3.6 billion in sales last year.

STMicroelectronics will retain 48.6 percent equity ownership, Intel will have 45.1 percent. Francisco Partners will invest $150 million in the venture for preferred stock representing a 6.3 percent stake.

Otto Warmbier was arrested in January 2016 at the end of a brief tourist visit to North Korea. He had been medically evacuated and was being treated at the University of Cincinnati Medical Center when he died at age 22.